Posted by: bgtwindad | September 3, 2010

On Dropping Feeder Wires

(Note: This is Part 1 of a 2-Part Series.  Part 2 can be found here.)

Now, I’m not saying this is the right way to add feeder wires to N scale track, but it’s the way I’m using, and so far it’s working well, if it’s not the most beautiful, unobtrusive method. So I thought I’d share, if at least to serve as a warning of how not to do this.

I’m using Atlas Code 80 flex track and turnouts, and 24 gauge 2-conductor intercom wire for my feeders.  I’m also dropping a feeder from every piece of track of any significant length, so I’m dropping a lot of them.  For those of you who don’t know, the feeders are the small-gauge wires that run from the track down to the main power bus for the track, which is usually a significantly larger gauge.  Feeder wires should be relatively short, so the small gauge is OK.

Many people use separate single-conductor feeder wires, one for each rail.  This is probably better than my method, if for no other reason than that the holes drilled through the roadbed are smaller.  But, I like having the wires paired under the bench, and I believe after ballasting this will end up looking pretty good.

Here we go!

Step 1: Tools

The tools I’m using:

  • Soldering iron, solder, rosin flux
  • Wire strippers and cutters
  • Small metric ruler
  • Hemostat
  • Alligator clips
  • Wire (24 gauge, 2-conductor intercom wire)

Tools for soldering feeder wires

Step 2: Prepare the wire.

I cut an 18″ length of wire, long enough to reach the longest distance from the track to one of the terminal strips I’m using to connect to my main bus.  Next, I clip the white conductor 10mm shorter than the black, and strip a short length off the ends of the wires.

Feeder wire prepared for soldering

If you like to tin your wire ends prior to soldering, now would be the time.

Step 3: Soldering the wires

Next, I bend the white lead and place it up against the outside of one rail.  I use a convention where all rails to the inside of my (oval) layout are on the white wire and all the outer rails are on the black wire.  This works because I have no reverse loops.  Those would require some slightly different convention.

Bend the wire, place it against the rail, and clip it in place with the hemostat.  Optionally add alligator clips to the rail on either side of the spot to act as heat sinks.  If you’re quick enough with the soldering, you won’t need them.

Make sure the bare wire is flush against the rail.  Add a dab of rosin flux, and solder the wire to the rail.  Be quick, but neat, and don’t use more solder than necessary, or it will be too obvious.

Feeder wire clipped to the rail and soldered

Once you’ve got the white wire in place, bend the black wire across under the ties and into place on the other rail.  Repeat the soldering process and stow your iron.

Black wire bent across under the ties

You’ll note that both feeders will now fit nicely through a single hole on the white side of the track.

Step 4: Installation

Now we are ready to install the track on the layout.  Lay the track in place, making sure it is exactly where you want it.  Then mark the spot where the feeder wire is and drill a hole for the wire.

Track test-fit on the layout, and feeder location marked for drilling.

Once the hole is drilled, cut a groove in the roadbed to accommodate the black wire running under the track.  This is important.  Without it, the black wire will create a bump in the track.

Feeder hole and notch in the roadbed.

Finally, feed the wire through the hole and glue the track into place.  As you can see, the wire is fairly unobtrusive, but not completely hidden.  You can fill the hole with some spackle or other material, and it should hide fairly well with ballast.

Track and feeder installed and glued.

In the above photo, the adhesive caulk has not cured and is still white.  Below is an overhead view of another installation after the caulk has cured.

Track and feeder installed and glued.

There are (at least) two drawbacks of this technique.  First, the hole for the paired wire is relatively large and will be harder to hide than two separate smaller wires.  Second, by soldering both rails to a pair of wires this way, the rails are located together and cannot be slid relative to each other.  So far, I have only used this on straight track segments and turnouts, so that has not been an issue.  I am not certain how well this will work with curves, but will report back soon, since I have several coming up.

(Go on to Part 2 of the series)


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